Cloudflare Workers will enable Request.signal by default

Cloudflare will switch on request.signal by default in Workers from 17 November. Any Worker with a compatibility date of 2026-11-17 or later gets client disconnection events automatically, without setting the enable_request_signal compatibility flag first.

The signal fires when the original client goes away mid-request, so you can log the cancellation, clean up resources, or pass the AbortSignal straight into an outgoing fetch() to stop work nobody is waiting for any more.

export default {
  async fetch(request) {
    request.signal.addEventListener('abort', () => {
      console.log('client disconnected');
    });
  },
};

Workers that keep an older compatibility date are unaffected. To try the new behaviour early, add enable_request_signal now; to keep the old behaviour after bumping your compatibility date past 17 November, add disable_request_signal.

Why it matters: if your Worker does meaningful work per request, long upstream calls, fan-out fetches, anything billed on CPU time, this is a free way to cut wasted work once a client bails. It is also a quiet behaviour change tied to your compatibility date, worth checking before you bump it.